How much HP for a 35-2?

Captnemo8

Captnemo8
Hello everyone I'm wondering what size diesel engines people have in your 35-2? I presently have a Grays marine gas engine which according to it's manual puts out 31 HP. I'm wanting to switch over to a Diesel and I'm getting all kinds of advice (salesman) as to the amount of HP I need?
Any help on this would be great???? P.S anyone have favorite brand?
Steve :esad:
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
power vs weight...

Per several on line sources, your displacement is about 11600#.
Since our boat is (before adding food, personal gear, etc) supposed to be 10500#, and we get by OK with the factory 23 hp diesel... I betcha you would be happy with that much hp.
In smooth water with little or no headwinds you could probably get by with an 18 or 20 hp engine. In a real world of contrary winds and waves and human timetables, I would not put in less than 25 to 28 hp if re-powering.

There is no single right or wrong answer...
I know that there is only so much room for the aux engine in the 35-2, but others on this site have posted up pictures of nice looking diesel conversions.
:cool:

Regards,
Loren
 

Emerald

Moderator
You're about 100 pounds off the displacement of the Independence 31, so I'd say my experience will be close to yours. I originally had a Yanmar 2QM15 in her. This was rated at 14hp continuous operation and 15 hp short term peak, and was really not enough to have any reserve. I could cruise around 5.5+ knots, but if I needed extra, had sea state, even a big wake, she would loose headway. I repowered with a Yanmar 3GM30F. It is rated for continuous operation at 24hp at 3400 RPM, and 27 hp for an hour at 3600 RPM. I cruise quiet comfortably around 6 knots at about 2800-3000 RPM, and have plenty of reserve (If I kick her up to 3400+, I move right along at something in the 6.3+ knot range, which is now hitting/passing hull speed). I would have to say this was a 100% satisfying repower on the results. I didn't have any particular engine in mind when I picked up the 3GM30F used, and had been looking for Universal engines as well. I think you would be fine with either, however, I will say I have been impressed with what seems to be very solid reliability out of the Yanmars, and they are easy to work on. My one complaint is the parts distribution is locked down tight, and you will not find any bargains, and some of the parts prices seem a bit steep to me. Felt like I was getting bent over on a thermostat and temperature sending unit I replaced a season back.
 
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ralph roddam

Member I
yes sir,I have an e35-2 that has been converted to Yanmar 3gm30f.Its located in the cabin and theres not a lot of room left.However the engine is very reliable and just about enough power.
 

Captnemo8

Captnemo8
Thanks

Thanks for the reply's everyone. Glad to have info from people with the same boat. Does anyone have an Engine "guy" that they trust to sell a good product for a working mans wage????
:egrin:
 

Greg Ross

Not the newest member
Ditto to Davids' thoughts and I took it a step further with the "Tim Allen approach to, you can never have too much horsepower"
Similar to Davids' set-up, the PO had replaced the original 2QM-15 with a 2GM-20 back in 1990, yielding around 17 hp.
My sailing waters are tidal and as well typically challenge us with Fall winds that can be pretty brisk. Based on 2 years experience in those conditions I wanted to be in the range of 30 hp and started looking at the next size up, the 3HM-35. Based on data sheet dimensions this engine is physically larger in length and width compared to the 3GM series including a wider bell housing. From measurements in the engine room I determined the larger engine would fit. Biggest consideration was bellhousing gearbox width relative to the existing mounting rails-they would have to be rescuplted to accomodate the 3HM.
In my case I had a serviceable 2 cyl. that was going to yield me some return at the completion of the swap and I was willing to consider "rebuilt/ used". Eventually found on eBay a rebuilt 3HM-35 with no gear that had been bought with similar intentions, the Seller in his situation simply could not shoehorn it into his hull. Seems to me he was replacing an atomic 4 (gas) thru a V-drive and it just would not fit.
Bought the engine and ordered a new Hurth 2:1 gear, that ratio having been selected as I was limited by the diameter of prop I could swing. The added HP had to be absorbed by higher prop rpm.
I probably could have tackled this swap myself but had the good sense to hire the talent to do it for me. The glasswork itself is a mean task and I elected to just look after the cleanup phase.
I went from a 13-9 3 blade prop thru 2.67-1 ratio gearbox up to a 14-10 3 blade thru 2-1 gear and it works like a charm. An acquaintance in the prop manufacturing business sized that combination for me. At 2800 rpm as I recall I`m making 5.5 kts and can push it to 3400 pounding into a big sea.
Final addition now is a feathering Max Prop for next year. Tradeoff is a drop in effeciency for the reduced drag under sail. And going astern with all that authority is going to be a treat.
 

rwthomas1

Sustaining Partner
Last winter I came very close to purchasing a new engine. I would have gone with a Betamarine. Why? They offered a replacement at a reasonable cost that had the correct mounts to simply BOLT INTO MY BOAT! No glasswork, etc. That makes a repower a much simpler job. Betamarine, while not that well known, uses Kubota parts. They also give you all the Kubota part numbers as well as all filter cross references, etc. so that service is a snap. Now I realize that many marinized diesels can be crossreferenced and parts from their terrestrial brethren sourced cheaper but the Betamarine way is much, much simpler. They also offered nice upgrades like Balmar alternators and serpentine belt drives, engine mounted oil changing pumps, etc. Did I buy a Betamarine? Nope, but if I had to I would have without hesitation.

RT
 
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